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Barium and neodymium isotopic anomalies in the Allende meteorite

McCulloch, M. T. and Wasserburg, G. J. (1978) Barium and neodymium isotopic anomalies in the Allende meteorite. Astrophysical Journal Letters, 220 (2). L15-L19. ISSN 2041-8205. doi:10.1086/182628.

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Isotopic anomalies have been found for Ba and N d in two inclusions from the Allende meteorite. These inclusions are typical Ca-Al-rich objects associated with early condensates from the solar nebula but have distinctive 0 and Mg isotopic anomalies of the FUN type. Sample C1 shows a depletion only in ^(135)Ba of 2 parts in 10^4 and normal Nd. Sample EK1-4-1 shows large positive excesses in the unshielded isotopes ^(135)Ba and ^(137)Ba of 13.4 and 12.3 parts in 10^4, respectively. The Nd isotopic composition in EK1-4-1 is highly aberrant in at least five isotopes. Both the Ba and Nd anomalies can be explained by a model of r-process addition. These anomalies are found to be uniform between coexisting mineral phases. These observations show the existence of substantial isotopic anomalies in refractory elements in the neighborhood of Xe and extend the range of elements showing isotopic effects to 0, Ne, Mg, Ca, Kr, Xe, Ba, and Nd. The observations, in conjunction with the presence of ^(26)Al (r_(1/2) = 7 X 10^5 years), are interpreted as the result of a nearby supernova explosion which produced elements over a wide mass range and injected them into the early solar nebula shortly before condensation.

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Wasserburg, G. J.0000-0002-7957-8029
Additional Information:© 1978 American Astronomical Society. Received 1977 October 14; accepted 1977 November 10. We are grateful to H. Nagasawa for the as yet unique sample of EK1-4-1. M. T. M. thanks D. A. Papanastassiou for his generous advice and introduction to high-precision mass spectrometry. D. J. DePaolo provided timely assistance and gave helpful advice. We thank R. Ward for his interest and advice on p's and q's and s and r. The excitement was communally shared with our calcined colleagues, D. A. Papanastassiou and Typhoon Lee. This work was supported by NSF grant PHY76-83685 and NASA grant NGL 05-002-188.
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NASANGL 05-002-188
Subject Keywords:meteors and meteorites - nucleosynthesis - stars: supernovae
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Caltech Division of Geological and Planetary Sciences2979
Lunatic Asylum Lab252
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Official Citation:Barium and neodymium isotopic anomalies in the Allende meteorite McCulloch, M. T. & Wasserburg, G. J. Astrophysical Journal, Part 2 - Letters to the Editor, vol. 220, Feb. 15, 1978, p. L15-L19.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:42127
Deposited By: Ruth Sustaita
Deposited On:30 Oct 2013 19:56
Last Modified:10 Nov 2021 16:18

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